Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
Dozens or hundreds of integrated circuits are typically manufactured on a single semiconductor wafer. The individual die are singulated by sawing the integrated circuits along a scribe line. The individual die are then packaged, separately, in multi-chip modules, or in other types of packaging, for example.
When the die are singulated, packaged, or handled, material layers can crack or delaminate proximate the scribe line, damaging the integrated circuits and leading to device failures. Crack prevention structures such as chip edge seal rings are often used near the edges of the die in an attempt to prevent cracking during singulation. However, crack prevention structures often fail to prevent cracks in some applications, resulting in reduced device yields.
Some cracks that may form in semiconductor devices may be difficult to detect. Other cracks may not be noticeable in the device performance until after die are packaged or used in an end application for a while, for example. The cracks may continue to perpetuate, eventually causing device failures.
Thus, what are needed in the art are methods and structures for detecting cracks in semiconductor devices.